Undersea antifouling treating composition

ABSTRACT

As an object and a use of an undersea antifouling treating composition provided by the invention, in order to prevent the adhesion of sessile organisms over a long period of time, the antifouling treating composition is immersed in fish nets for culturing, trapping and the like immersed in sea for a long time and materials such as rope and the like supporting these nets, a net for preventing invasion of jellyfishes at an intake port for cooling water, a curtain for the prevention of marine pollution used in seaside working and the like.

TECHNICAL FIELD

This invention relates to a novel undersea antifouling treating composition for treating a fibrous or rope-like material to be immersed in sea.

BACKGROUND ART

Fish nets for culturing, trapping and the like immersed in sea for a long time and materials such as rope and the like supporting these nets, a net for preventing invasion of jellyfishes at an intake port for cooling water, a curtain for the prevention of marine pollution used in seaside working and the like are immersed in sea over a long period of time.

As a result, they are fouled by sessile organisms in sea to cause problems such as clogging of mesh in the net, infection of various fishes with sickness or parasite due to the decrease of flowing quantity of sea water, damage by the increase of weight, decrease of floating force and the like.

As a method of preventing the fouling through such sessile organisms, there has hitherto been widely used an undersea antifouling treating composition containing an organic tin compound such as TBT (tributyl tin compound) or the like as an effective ingredient. However, the tendency of self-control in use or the like is widening from a doubt of storing the effective ingredient in circumstance or the like.

On the other hand, as an antifouling treating composition containing no organic tin compound, there are disclosed a) a technique using a dialkylpolysulfide compound as an effective ingredient in Japanese Patent Application Publication No. 62-43962, and b) a technique on an antifouling treating composition for fish nets containing tetraalkyl thiuram disulfide, dialkylpolysulfide, 2-(thiocyanomethylthio) benzothiazole and the like as an effective ingredient in Japanese Patent laid open No. 60-38306, respectively.

Apart from the above techniques, the inventors have proposed c) a technique on an undersea antifouling treating composition containing a copolymer indicating a particular hydrophilic property and thiocyano alkylthiobenzohetrozole in Japanese Patent laid open No. 1-178562.

However, the effective antifouling performances can not be obtained only by the dialkylpolysulfide compound disclosed as the above technique a, while the tetraalkyl thiuram disulfide, dialkylpolysulfide and 2-(thiocyanmethylthio) benzothiazole disclosed as the above technique b shortly show effective antifouling performances, but it is very difficult to elute a sufficient amount of the effective ingredient from the fish net treating agent over a long period of time. Further, it has been confirmed that only the copolymer indicating the particular hydrophilic property and the thiocycno alkylthiobenzohetrozole previously proposed by the inventors as the above technique c are still insufficient to maintain the effective antifouling performances over a long period of time.

An object of the invention is to provide an undersea antifouling treating composition which can necessarily and sufficiently control the eluting rate of an antifouling agent from the fibrous or rope-like materials immersed in sea over a long period of time.

DISCLOSURE OF THE INVENTION

The inventors have made various studies in order to achieve the above object and found that dialkylpolysulfide or dialkylpolysulfide and polybutene are added as an eluting controller to an undersea antifouling treating composition comprising a particular antifouling agent and a resin as well as various film forming substances, whereby the eluting rate of the above antifouling agent can necessarily and sufficiently be controlled over a long period of time, and as a result the invention has been accomplished.

That is, the invention is concerned with a first invention on an undersea antifouling treating composition comprising the following ingredients A-C;

A) at least one of the following components A1-A5;

A1: 2-(thiocyanomethylthio) benzothiazole,

A2: tetraethylthiuram disulfide,

A3: 2,4,5,6-tetrachloro-1,3-dicyanobenzene,

A4: N-(ethylmethylphenyl)-dichloromaleimide,

A5: N-(diethylphenyl)-dichloromaleimide,

B) film forming substance;

C) at least one of dialkylpolysulfides represented by the following general formula (1);

    R.sub.1 --(S).sub.n --R.sub.2                              ( 1)

(wherein each of R₁, R₂ is an alkyl group having a carbon number of 1 to 20 and n is an integer of 1-5), and is preferably concerned with a second invention on an undersea antifouling treating composition comprising the above ingredients A-C and further

D) polybutene having a polymerization degree of 2-100.

BEST MODE OF CARRYING OUT THE INVENTION

The ingredient A as an antifouling agent in the undersea antifouling treating composition according to the invention is at least one of 2-(thiocyanomethylthio) benzothiazole, tetraethylthiuram disulfide, 2,4,5,6-tetrachloro-1,3-dicyanobenzene, N-(ethylmethylphenyl)-dichloromaleimide and N-(diethylphenyl)-dichloromaleimide. All of these agents are well-known as an antifouling agent having a low toxicity.

As the ingredient B used as the film forming agent in the undersea antifouling treating composition according to the invention, mention may be made of natural resin for general-purpose paint, rosin, modified rosin, fatty acid, oily varnishes usually used, synthetic rubber, chlorinated rubber, polyvinyl chloride, styrene-butadiene copolymer, acrylic resin and the like. Furthermore, acrylic hydrophilic polymers synthesized by using particular hydrophilic monomers as mentioned in the following production examples are preferably used.

The ingredient C used as an eluting controller in the undersea antifouling treating composition according to the invention is at least one of dialkylpolysulfides represented by the following general formula (1);

    R.sub.1 --(S).sub.n --R.sub.2                              ( 1)

(wherein each of R₁, R₂ is an alkyl group having a carbon number of 1 to 20 and n is an integer of 1-5). This is generally used as a high-pressure additive for cutting oil and is a substance showing no inhibition action to organisms. As a concrete example, there are mentioned di-t-nonyl pentasulfide (specific gravity: 1.03), di-t-dodecyl pentasulfide (specific gravity: 1.55) and the like.

Further, the ingredient D used as another eluting controller in only the undersea antifouling treating composition according to the second invention is a polybutene having a polymerization degree of 2-100. This is generally used as a resin softening agent, a sizing agent or other and is a substance showing no inhibition action to organisms. As a concrete example, there are mentioned various Nissan Polybutenes (polybis) such as Polybutene 06N, Polybutene 15N (made by Nippon Oil and Fats Co., Ltd.) and so on.

As the amount of each ingredient used in the undersea antifouling treating composition according to the invention, the ratio occupied in the treating composition is 0.3-60% by weight, preferably 0.5-50% by weight in the ingredient A, 3-60% by weight, preferably 5-30% by weight in the ingredient B and 1-30% by weight, preferably 2-25% by weight in the ingredient C, and further 1-30% by weight, preferably 2-25% by weight in the ingredient D in the treating composition of the second invention.

When the amount of the ingredient A is less than the above value, the antifouling property is lacking, while when it is too large, the formation of the coating is difficult. When the amount of the ingredient B is too small, the formation of the coating is difficult, while when it is too large, the antifouling property is lacking and the function of eluting control lowers. When the amount of the ingredient C is too small, the function of eluting control lowers, while when it is too large, the function of eluting control also lowers and the formation of the coating is difficult. When the amount of the ingredient D is too large, the function of eluting control lowers and the formation of the coating is difficult.

In the undersea antifouling treating composition according to the invention, various additives such as organic solvent, other antifouling agent, colorant, thixotropic agent, antifoaming agent, thickening agent, plasticizer and the like may be added, if necessary, in addition to the above ingredients A-D.

As the organic solvent, toluene, xylene, solvent naphtha, pseudocumene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, ethyl cellosolve, butyl cellosolve and the like may be used alone or in admixture thereof.

In order to improve the antifouling property, the other antifouling agent such as N-t-butyl-N'-cyclopropyl-6-(methylthio)-1,3,5-triazine-2,4-diamine, 3-(3,4-dichlorophenyl)-1,1-dimethylyrea, N,N-dimethyl-N'-phenyl-N'-(fluorodichloromethylthio) sulfamide, N,N-dimethyl-N'-tolyl-N'-(fluorodichloromethylthio) sulfamide, N-(fluorodichloromethylthio) phthalimide, cuprous oxide, organotin compound, zinc dimethyldithiocarbamate, copper diethyldithocarbamate and the like may be added within a range of damaging no effect of the invention.

The undersea antifouling treating composition comprising the ingredients A-C or the ingredients A-D according to the invention is usually prepared by dissolving the above ingredients in an organic solvent by means of a dissolver or the like. The prepared undersea antifouling treating composition is immersed in a material to be treated.

The invention will be concretely described with reference to production examples, examples, and comparative examples. In the examples, part and % are by weight.

PRODUCTION EXAMPLES 1-3

Into a flask provided with a stirrer were charged solvent 1, unit B1, unit B2 and catalyst 1 according to a compounding recipe shown in Table 1, and temperature was raised to 100° C. for 30 minutes with stirring and further the stirring was continued at the same temperature for 2 hours. Then, a mixed solution of additional solvent 2 and catalyst 2 was added dropwise over 1 hour, and the stirring was continued at 105° C. for 2 hours and at 120° C. for 1 hour.

Finally, a diluent was added and homogenized to obtain each of three transparent hydrophilic copolymer solutions. The solid content, viscosity and molecular weight of the polymer solution were shown in Table 1.

                  TABLE 1                                                          ______________________________________                                                         Produc-                                                                               Produc-  Produc-                                                        tion   tion     tion                                                           Example                                                                               Example  Example                                                        1      2        3                                              ______________________________________                                         Solvent 1                                                                             xylene         60       60     60                                       Unit B1                                                                               ethoxypentadeca-                                                                              10                                                              ethylene glycol                                                                methacrylate                                                                   methoxytricosa-                                                                               5               2                                               ethylene glycol                                                                methacrylate                                                                   2-methoxyethyl                 3                                               acrylate                                                                       propioxytetradi-        21.5                                                   ethylene glycol                                                                methacrylate                                                                   2-acetoxyethyl          21.4                                                   acrylate                                                                Unit B2                                                                               methyl         35       30     50                                              methacrylate                                                                   methyl n-butyl 50       22.1                                                   methacrylate                                                                   2-ethylhexyl acrylate          45                                              styrene                 5                                               Catalyst                                                                              t-butylperoxy-2-                                                                              1.5                                                      1      ethylhexanoate                                                                 benzoyl peroxide        1.5    1.5                                      Catalyst                                                                              t-butylperoxy-2-ethyl                                                                         0.5                                                      2      hexanoate                                                                      benzoyl peroxide        1.5    1.5                                      Solvent 2                                                                             xylene         20       20     20                                       Diluent                                                                               xylene         20       20     20                                       Property                                                                              viscosity      1.3      1.0    1.2                                      value  (poise/20 degree)                                                              solid content  62.0     49.2   48.8                                            (weight %)                                                                     weight average 73,000   23,000 28,000                                          molecular weight                                                        ______________________________________                                    

Examples 1-18 and Comparative Examples 1-26 Preparation of undersea antifouling treating composition

Various treating compositions of Examples and Comparative Examples were prepared by charging all ingredients into a beaker according to a compounding recipe shown in Table 2 and stirring and dissolving them by means of a dissolver.

                                      TABLE 2(1)                                   __________________________________________________________________________              Example                                                                        1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17 18                 __________________________________________________________________________     Production                                                                              24.2              24.2                                                                              24.2                                                                              24.2                                                                              24.2                                                                              8.0      8.0      20.0                  Example 1                                                                      Production  30.0                          61.0     20.0     61.0               Example 2                                                                      Production     30.0                          40.0     40.0                     Example 3                                                                      Acrylic           15.0                                                         resin                                                                          Vinyl                15.0                                                      chloride                                                                       Chlorinated             15.0                                                   rubber                                                                         TCMTB    10.0                                                                              10.0                                                                              10.0                                                                              10.0                                                                              10.0                                                                              10.0           0.5                                                                               10.0                                                                              1.5                                                                               0.5   2.0   10.0               TET                        10.0        30.0                                                                              1.0                                                                               10.0  50.0                        TCDCB                         10.0                 5.0                         EMDCM                            10.0                 10.0                     DEDCM                               10.0                 12.0                  TNPS     5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               25.0  10.0                                                                              5.0                                                                               2.0                                                                               25.0                                                                              5.0                   TDPS                                      2.0               10.0               PBO6N    5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0                                                                               5.0         5.0                                                                               2.0                                                                               5.0                                                                               25.0                                                                              5.0                xylene   55.8                                                                              50.0                                                                              50.0                                                                              65.0                                                                              65.0                                                                              65.0                                                                              55.8                                                                              55.8                                                                              55.8                                                                              55.8                                                                              36.5                                                                              26.0                                                                              38.5                                                                              81.5                                                                              21.0                                                                              18.0                                                                              38.0                                                                              14.0                        100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0              __________________________________________________________________________

                                      TABLE 2(2)                                   __________________________________________________________________________              Comparative Example                                                            1  2  3  4  5  6  7  8  9  10 11 12 13 14 15                          __________________________________________________________________________     Production                                                                              4.0                                                                               24.2                                                                              24.2  24.2                                                                              24.2  24.2                                                                              24.2  24.2                                                                              24.2                                                                              24.2                                                                              24.2                                                                              24.2                        Example 1                                                                      Production        10.0                                                         Example 2                                                                      Production                 10.0                                                Example 3                                                                      Acrylic                                                                        resin                                                                          Vinyl                                                                          chloride                                                                       Chlorinated                         65.0                                       rubber                                                                         TCMTB    0.5                                                                               10.0                                                                              10.0                                                            TET               0.1                                                                               10.0                                                                              10.0                 65.0                              TCDCB                      0.5                                                                               10.0                                                                              10.0                                          EMDCM                               2.0                                                                               10.0                                                                              10.0                                 DEDCM                                           10.0                                                                              10.0                        TNPS     25.0     25.0     40.0                                                PBO6N       10.0     10.0     10.0     10.0     10.0                           xylene   70.5                                                                              55.8                                                                              65.8                                                                              64.9                                                                              55.8                                                                              65.8                                                                              49.5                                                                              55.8                                                                              65.8                                                                              33.0                                                                              55.8                                                                              65.8                                                                              10.8                                                                              55.8                                                                              65.8                                 100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                       __________________________________________________________________________

                                      TABLE 2(3)                                   __________________________________________________________________________                Comparative Example                                                            16 17 18 19 20 21 22 23 24 25 26                                    __________________________________________________________________________     Production Example 1                                                                      4.0            24.2  24.2                                                                              24.2                                        Production Example 2                                                                         20.0  5.0                                                                               10.0                                                    Production Example 3                                                                            20.0        20.0                                              Acrylic resin                         65.0                                     Vinyl chloride                           65.0                                  Chlorinated rubber                                                             TCMTB         0.1                                                              TET              65.0                                                                              0.5   65.0                                                 TCDCB                  0.1   50.0                                                                              10.0                                                                              10.0                                        EMDCM                                 2.0                                                                               2.0                                   DEDCM      10.0                                                                TNPS             10.0                                                                              10.0                                                                              10.0                                                                              2.0                                                                               0.5                                                                               40.0                                                                              10.0                                                                              10.0                                                                              10.0                                  PBO6N               10.0                                                                              10.0                                                                              2.0                                                                               2.0                                                                               10.0                                                                              40.0                                                                              10.0                                     xylene     86.0                                                                              79.9                                                                              5.0                                                                               74.5                                                                              69.9                                                                              6.8                                                                               27.5                                                                              15.8                                                                              15.8                                                                              13.0                                                                              23.0                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                 __________________________________________________________________________     (Note)                                                                                 solid content                                                          resin   in resin %                                                                            trade name                                                      Acrylic resin                                                                          100.0  Hitaloid 1641A                                                                         made by Hitachi Chemical Industries, Ltd.               Vinyl chloride                                                                         100.0  Eslec C made by Sekisui Chemical Co., Ltd.                      Chlorinated                                                                            100.0  Aroprene R20                                                                           made by Imperial Chemical Industries, Ltd.              rubber                                                                         Reagent                                                                              substance name                                                           TCMTB 2-(thiocyanomethylthio)                                                                    made by Permachem Asia Kabushiki Kaisha                            benzothiazole                                                            TET   tetraethylthiuram                                                                          made by Sanshin Kagaku Kogyo Kabushiki Kaisha                      disulfide                                                                TCDCB 2,4,5,6-tetrachloro-1,                                                                     made by Sannobuko Kabushiki Kaisha                                 3-dicyanobenzene                                                         EMDCM N-(ethylmethylphenyl)-                                                                     made by Nippon Oil and Fats Co., Ltd.                              dichloromaleimide                                                        DEDCM N-(diethylphenyl)-                                                                         made by Nippon Oil and Fats Co., Ltd.                              dichloromaleimide                                                   

The test for antifouling property through immersion in sea and the measurement on an amount of antifouling agent eluted were made with respect to the above prepared treating compositions of examples and Comparative Examples. The results were shown in Table 3.

Test for antifouling property

A specimen of 20 cm in width and 40 cm in length cut out from a polyethylene fish net for culture fishpond (32 nets, 6 knots) was immersed in each of the undersea antifouling treating compositions of Examples and Comparative examples and then dried in air for 48 hours. The fish net treated by the above method was immersed at a position of 1.5 m beneath water surface in Aioi port of Hyogo prefecture, and then the fouled state through sessile organisms was examined over 6 months. The results of the test for antifouling property were evaluated at the following five stages.

5: no fouling of sessile organisms.

4: area of sessile organisms fouled to the fish net is less than 5%.

3: area of sessile organisms fouled to the fish net is not less than 5% but less than 15%.

2: area of sessile organisms fouled to the fish net is not less than 15% but less than 50%.

1: area of sessile organisms fouled to the fish net is not less than 50%.

Amount of antifouling agent eluted

The same fish net as used in the test for antifouling property was impregnated with the treating composition in the same manner and immersed in sea. After 6 months, the fish net was taken out from sea and placed in a beaker containing 1 liter of sea water for 1 hour to elute the antifouling agent. The sea water containing the eluted antifouling agent was analyzed by a liquid chromatography to measure the amount of the antifouling agent eluted. The eluted amount was indicated as a concentration of the antifouling agent eluted in 1 liter of sea water (ppm).

                                      TABLE 3                                      __________________________________________________________________________            Test result of                                                                 antifouling property                                                                       Amount of antifouling                                              1   3   5   agent eluted (ppm)                                                 month                                                                              months                                                                             months                                                                             TCMTB                                                                               PET                                                                               TCDCB                                                                               BMDCM                                                                               DEDCM                                     __________________________________________________________________________     Example                                                                         1     5   5   5   0.15                                                         2     5   5   4   0.12                                                         3     5   5   5   0.14                                                         4     5   4   3   0.09                                                         5     5   4   3   0.10                                                         6     5   4   4   0.12                                                         7     5   4   3        0.09                                                    8     5   4   3           0.09                                                 9     5   4   4                0.10                                           10     5   4   4                     0.09                                      11     5   4   3   0.09 0.09                                                   12     5   3   4   0.15 0.07                                                   13     5   3   3   0.12 0.09                                                   14     5   5   4   0.09                                                        15     5   5   4        0.10                                                                              0.10                                                16     5   4   5   0.13         0.11                                           17     5   5   4                     0.10                                      18     5   4   5   0.15                                                        Comparative                                                                    Example                                                                         1     3   2   1   0                                                            2     5   2   1   0.01                                                         3     3   1   1   0                                                            4     1   1   1        0.01                                                    5     5   3   1        0                                                       6     3   1   1        0                                                       7     2   1   1           0                                                    8     5   3   1           0.01                                                 9     2   1   1           0                                                   10     1   1   1                0                                              11     5   4   2                0.03                                           12     3   1   1                0                                              13     5   1   1                     0.02                                      14     5   3   1                     0.01                                      15     3   1   1                     0                                         16     4   1   1                     0.01                                      17     2   1   1   0                                                           18     5   1   1        0                                                      19     2   1   1        0                                                      20     1   1   1           0                                                   21     5   1   1        0                                                      22     5   4   1           0                                                   23     5   2   1           0                                                   24     5   2   1           0                                                   25     2   1   1                0                                              26     1   1   1                0                                              __________________________________________________________________________

As seen from Table 3, in Examples 1-10, 14-18 being the undersea antifouling treating compositions according to the second invention, no fouling of sessile organisms was observed even in the test for antifouling property for 6 months, and the eluted amount of the antifouling agent of 0.09 ppm was maintained even after 6 months.

In Examples 11-13 being the undersea antifouling treating compositions according to the first invention, the antifouling property was slightly poor as compared with the second invention, but the adhesion of sessile organisms in the test for antifouling property was slight over a long period of 6 months and the eluted amount of the antifouling agent of 0.07 ppm was maintained after 6 months.

On the other hand, in the comparative examples, the remarkable fouling of sessile organisms is observed and the eluted amount of the antifouling agent after 6 months clearly decreases, from which it is clear that the undersea antifouling treating composition according to the invention is excellent.

INDUSTRIAL APPLICABILITY

In the fibrous or rope-like materials treated with the undersea antifouling treating agent containing the ingredient C or further the ingredient D according to the invention and immersed in sea, the eluting rate of the ingredient A as an antifouling agent is adequately controlled, so that the antifouling effect can be maintained over a long period of time, which has never been attained in the conventional technique. 

We claim:
 1. An undersea antifouling treating composition comprising:A) 0.3 to 60% by weight of at least one antifouling agent selected from the group consisting of: 2-([thiocycanomethylthio]thiocyanomethylthio) benzothiazole, N-(ethylmethylphenyl)-dichloromaleimide, and N-(diethylphenyl)-dichloromaleimide; B) 0.3 to 60% by weight of a film forming substance; and C) 1 to 30% by weight of at least one dialkylpolysulfide represented by formula (1:

    R.sub.1 --(S).sub.n --R.sub.2                              ( 1)

(wherein each of R₁ and R₂ is alkyl having a carbon number of 1 to 20 and n is an integer of 1-5).
 2. An undersea antifouling treating composition according to claim 1, further comprising:D) 1 to 30% by weight of polybutene having a polymerization degree of 2-100. 